Explicit action versions

Login and push to ghcr too

.github/workflows/docker.yml

@@ -16,22 +16,30 @@ jobs:
     steps:
       -
         name: Checkout source code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v2.3.4
       -
         name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v1
+        uses: docker/setup-buildx-action@v1.5.1
       -
         name: Login to DockerHub
-        uses: docker/login-action@v1
+        uses: docker/login-action@v1.10.0
         with:
           username: ${{ secrets.DOCKER_USER }}
           password: ${{ secrets.DOCKER_PASSWORD }}
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v1.10.0
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
       -
         name: Build and push
         id: docker_build
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v2.6.1
         with:
           context: .
           push: true
-          tags: esphome/esphome-docs:latest
-          cache-from: esphome/esphome-docs:latest
+          tags: |
+            esphome/esphome-docs:latest
+            ghcr.io/esphome/esphome-docs:latest
+          cache-from: ghcr.io/esphome/esphome-docs:latest